Method of reducing the octane demand of engines



United States Patent C MErHoD orr RED'UCING THE ocT'ANE DEMAND or ENGINES Everett C., Hughes,- Shaker Heights,0hio, assignor `to `The Standard Oil Company, Cleveland,l Ohio, a corporation of Ohio i '(Cl. 1232-1) f Thefpresent inventin relates to amethod, ofv reducme octanejdemand of 'a vvdirty internal: combustion Aengi 'e by removing deposits from Ithe Surfaces of the `tion `chamber or vcharnbers thereof ina simple, safe and Leffectivemanner that vdoes not require dis- :manning 0f the 'engine It is well. ktlfvvil, .that depsits quickly. accumulate in the combustion chambers `-of internal combustion engines such as those used in automobiles. An engine with deposits requires the use of a gasoline with a higher octane rating than does a clean engine if the engine is not to knock, and the dirty engine is said to have a Vhigher octane demand. This becomes apparent to the driver of 'an old automobile by the knocking jof the engine while accelerating, climbing va hill 'or otherwise operating the engine undergreater than normal load. The deleterious effects of such accumulations of deposits are particularly noticeable in engines having a high compression ratio because the margin between the octane number of gaso- `lines on the market and thevoctane demandof the "engine whenY clean is narrower than for engines having lower compression ratios. d v i L A great 'number of methods hai/ e been `proposed here- .jtofore for cleaning the combustion chambers of an, in-

ternal combustion engine. One of these'methods is that jof introducing aliquid solventinto the carburetor while 'the engine is running. Altholfigh this method produces great billows of smoke at theexhaust, it has been found, upon taking an engine so treated apart after the operation, that little of the vdeposits are'actually lremoved.

Another 'of these methods described in' prior patents is that of inserting metal objects such as chains and the like into the various cylinders through the sparl plug holes, .replacing lthe `spark plugs, vrunning, 'the engine, i and 'then removing the chains `or other similar objects. IrThis method of operation has `been found 'entirely impracltic'able because. (a) the'seobjects generally are so vhard and non-crushable as rto cause injury to 'the engine if jammed between moving parts such as a valvehead; (b)

the number of particles introduced n'to each cylinder at one timeiseither so great as to interfere seriously "with 'the "combustion and the movement 'of the valves and "piston, orso'smallthat the spark'plugfor each cylinder Willh'ave to be removed and replaceds'o voften during "a single cleansing as to make excessive the time required for the operation and the probability of injuryto jthe Aspark plugs; (cf) many of the particlesroll o ut through ithe valves before the engine'gains sutlicientspeed tomake `them effective, thusresulting in a waste of particles and in an accumulation thereof in the exhaust manifold and minder; and(d) the noise of the operation has 'caused :some concern on the part of consumers, and forth'e further reason that consumers would'iobjectto'havingfmetal .particles placed in the combustion chambers of their ngn'e's. n i

In view of the failure of the many methods proposed `inprior patents bf which the foregoingare butau few,

it is still standard practice to, clean an internal vcombusposits away frorn the tops of the pistons and valyes and "the recesses "in the cylinderhead'formingl vthe confining useless'for at least a day.

nowi'been'found'tlat' does not require'a lifting 'of "the-cylfsynthetic resins, clay, sodium silicate, bor'a x,j

inexpensive'y Aand requires lverylr l hlod involyeshintrcdncing intct be'rpf anwen'girie a plurality of 'scre't particles e n'- tially comprising graphite, and running 'the engine "wlth said particles in the combustion chamber' `to rem'v the deposits. Y l l WBecau's'e of` the `relative fragility and lw *specific ity of particles essentially and 'primarilyc6` 'rising g p ite, there is practically no vIirnit 't the of the 'iiidividual particles that may be used "ac rdaiic with 'the method 'of this invntibn, prvide "they canjbe fin.- troduced in the mnner described he'rel yh 4i'f thenparticles or somep of them, have a ension 'larger tharnth'e' ininimurnclearance vinthe c bii'sftion chamber between the -piston 'and the cylindr head, or if any of said particlesy should be vja'rnri'ed between vany relatively moving metal surfaces, such as for examplcvalveand a valve seat, such particles would be crushed without damage to the metal surfaces` There is also no limit to the shape that the particles may have, Thus, for example, `they may 'be cubes, (cylinders, illipsoids, spheres and the like. One shape that has been found to beeparticlularly effective and suitable, primarily because it is the :shape in which,A graphite particles are most 'readily available, is the cylinder. The particles Apreferred for the purposes of the present invention are'cylindcs es",- sentiallycomprising graphite and having a diameter of vabout 1m and lengths ranging from about Ms to'abo'ut The hardness of 'the vparticlesfis "not critical, however, harder graphite particles 'are more 'effective because they are not pulverized as quickly in the combustion chambers. Some desirable effects in reducing octane :demand fare obtained with graphite pellets `that are as fsoft fas the graphite of a No. l lead pencil. The lhardest known ygraphite particles have been tested `and foiir1d-t*be-ef fectlve without 1n, any sense lcausing injury to 'the'engine The fparticle's may consist ventirely or primarily lof graphite. lThey/amy, and desirabiy do, when, rin adition to "the graphite, such binders as coal tat -pith,

and the like. One type "of particlethatfhasbelen oundentirely `Suitable is prepared by heating petroleum 'coke to drive 'on venute-matter, grindingit to a po der and mi'xngit with sufficient coal tair'pit'ch "to mak "the compositionV plastic enough for extrusion. Thereafter rods of approximately l ft. in length and about Vs" in diameter are extruded, baked at a high terip'eratur'cf'f the order of 1 000 to 2500 C. and then cut to lengths of approximately 1/8 to 1%[62 The term non-liquid, non-powder form as 'used in the claims is intended to distinguish the discrete particles used in practicing the invention from graphite in a colloidal or similar liquid form and from powdered graphite. H

The method of the invention is most effectively carried out by introducing the vparticles into the engine lthrough the carburetor, with the anfilter removed, and

the intake manifold for distribution among the engine cylinders. This is accomplished by pouring the lparticles in a steady stream in fairly uniform increments into the carburetor `past the butterfly valve while the engine is run ata fairly `high speed. The method 'is preferably carried out in such a manner that approxi- *matelyv to 300 particles percylindera're introduced within approximately l to l0 minutes or atan overall rate of'between about 7.5 and `60 particles per'minute per cylinder. The rate and amount should not be so great as to cause the engine "to stop during the cleaning operation.

The introduction 4of the particles can be accomplished by means of a suitabledispen'ser or by the continal addition of pinches of say about 5 to 40 particles i ch. The advantages 'of thisjmethod 'o'ffcleanng "n fin'- ternal combustion engine rare numeroug The vmethod is extremely simple and may be carried out in less ytime than it takes to have the oil changed. Asshown in the examples hereinafter, the method iseffective in reducing as muchas '65% of the octane requirement increase 'ofa dirty enginey and inf'ihcreasing its" p'ower'otput by as much as 15%. It does not require a lifting of the cylinder head and the preferred embodiment of the method does not even require the removal of the spark plugs. The method does not alarm the customer because it is not noisy and it is a matter of common knowledge among customers that graphite has lubricating value. The method is not at all harmful to the engine but in fact lubricates the engine parts. In addition to its many desirable effects, the most apparent of which is the reduction in octane requirement and increase in power output of the engine, the method also appears to have desirable effect of reducing the rate at which the octane requirement of the engine will increase after normal operation is resumed. Finally, but by no means least important, the method has the advantage of utilizing particles of a material that is not critical, as are lead, copper and other metals, in time of war or national emergency.

These and other advantages, as well as the utility of the method of this invention, will become more apparent from the following examples, it being understood that these examples are illustrative only and not limitative of the scope of the invention.

Example 1 A standard Chevrolet passenger car engine was run on a test stand for 109 hours (equivalent to about 4360 miles at a conversion of 40 miles per hour) during which the octane requirement of the engine increased from 74 to 85. At the end of that time approximately 1500 graphite particles, made from petroleum coke and coal tar pitch, extruded, baked and cut as previously described, and having a diameter of about Ms" and lengths ranging from about Ms" to 5&6, were introduced within an interval of about 5 minutes on each side of the buttery valve in the throat of the carburetor It was found that this treatment reduced the octane requirement of the engine by 4 and increased the power output by 2.3%.

The engine was then run for an additional 111 hours, during which time the octane requirement increased, at a slower rate than in the first part of the run, from 8l to 87 At the end of that time the test treatment with graphite particles was repeated and it was found that the octane requirement of the engine was reduced by 9 and that the power output was increased by The engine was then run for an additional 120 hours. lt was found that in this part of the run the treatment had also reduced the rate of octane requirement increase. Upon subsequent dismantling of the engine, careful inspection showed that no harm had been done to any of the parts.

Comparison of the rate of increase of octane requirement before the first treatment with the rate of increase after the first and second treatments with graphite partiA cles, demonstrates the lasting effect of the treatment in reducing the rate at which the octane requirement increases with further operation.

Example 2 A total of five tests were carried out with standard Chevrolet passenger car engines. Each test was begun with a clean engine whose octane requirement was determined. Each engine was then run until its octane requirement ceased to increase further to any appreciable degree. The octane requirement increase of the engine and its brake horsepower were then determined. Thereupon, approximately 1500 graphite particles were introduced in the same manner as described in Example 1.

following which the octane requirement and the brake horsepower of the engine were determined by standard TheV results in tests Nos. 4 and 5, which are superior to those obtained in tests Nos. 1, 2 and 3, are believed due to the fact that in those tests graphite particles were used which are harder than those used in tests Nos. 1, 2 and 3. These harder particles are the hardest developed lately and available from the National Carbon Division of the Union Carbon and Carbide Corporation.

Test No. 5 shows that the method of the invention is capable of reducing the octane requirement by of the possible reduction and the results of test No. 4 indicate 1tlat the power output may be increased by as much as o.

The method described above was further evaluated in a series of standard cars of various makes indicated in the first column of the following table, which had been driven for the number of miles indicated in the second column of the table. The octane requirement of each car before being treated in accordance with the invention was measured and this is indicated in the third column. Each car was then cleaned utilizing the graphite pellets in the manner described heretofore. The octane requirement of each car was measured after the cleaning and this is indicated in the fourth column. The octane requirement reduction is indicated in the fifth column. The per cent power increase at 15 to 35 miles per hour acceleration was also determined before and after the cleaning method of the invention and the percentage ingrl'ease is indicated in the last column of the following ta e:

Table II Percent Octane Octane Ogfm Power Re- ReuirB Increase Car Type Mileage quirequire- 11mm at 15-35 ment ment Reduc M. 1. H. Before After tion Acceleration Chevrolet-1948 31, 443 87 83 4 5. 5 Plymouth-1948 23, 002 79 75 4 d. 5 Chevrolet-1951 8, 915 83 80 3 3. 5 Dod 1949 18, 525 83 75 8 2.0 Ford 6-1949 40, 061 79 73 6 2.0 Plymouth-1948 25, 443 85 S0 5 d. 0 Nash (Rmn)-1951.-.. 24, 344 85 83 2 .5 Ford TW-1950 16, 706 77 73 4 1.0 P1ym0l1th-1949 19, 319 84 80 4 1. 5 Ford V-81950 14, 470 78 T3 5 3. 5 Packard-1949. 03, 946 89 87 2 4.0 Ford V8-194 54, 337 81 75 4. 5 Kaiser 0 25, 975 83 77 (l) Buick 81948 155 84 80 4 2. 0

l Not measured.

It is apparent that many variations and modifications will occur to those skilled in the art upon reading the foregoing description. All those variations and modifications are intended to be included within the scope of this invention as defined in the appended claims.

l claim:

1. A method of reducing the octane requirement of a dirty internal combustion engine which comprises introducing into the combustion chamber of an engine, a plurality of discrete particles in non-liquid, non-powder form, essentially comprising graphite, and running the engine with said particles in the combustion chamber to remove deposits therefrom.

2. The method of claim l in which the particles are introduced through the intake manifold of the engine for conveyance to the engine cylinders while the engine 1s running.

3. The method defined in claim 2 wherein the discrete particles are introduced into the intake manifold through the throat of the carburetor.

4. The method defined in claim 2 wherein the number of particles introduced is between about and 300 p r 1 6 engine a fuel charge and a charge of discrete particles References Cited in the le of this patent in ngn-liquid, non-powder form, essentially comprising UNITED STATES PATENTS grap ite.

9. The method defined in claim 8 wherein the discrete Number Name Date particles are introduced into the intake manifold through 5 1,995,762 Williams Mar. 26, 1935 the throat of the carburetor. 2,002,834 Rolen May 28, 1935 10. The method dened in claim 8 wherein the number 2,178,932 Daniels Nov. 7, 1939 of particles introduced is between about 75 and 300 per 2,216,106 Balkwill Oct. 1, 1940 cylinder, 

1. A METHOD OF REDUCING THE OCTANE REQUIREMENT OF A DIRTY INTERNAL COMBUSTION ENGINE WHICH COMPRISES INTRODDUCING INTO THE COMBUSTION CHAMBER OF AN ENGINE, A PLURALITY OF DISCRETE PARTICLES IN NON-LIQUID, NON-POWDER FORM, ESSENTIALLY COMPRISING GRAPHITE, AND RUNNING THE ENGINE WITH SAID PARTICLES IN THE COMBUSTION CHAMBER TO REMOVE DEPOSITS THEREFROM. 